The (IPT) is hearing complaints against the agencies after evidence was released showing how legally privileged material was viewed by security officials.
The case has been brought forward by two Libyan men, Abdel-Hakim Belhaj and Sami Al Saadi and their families, after they were detained in a joint MI6-CIA operation and sent back to Libya, where they were tortured by officials of Muammar Gaddafi's regime.
Behaj has been given permission to sue the UK government for their complicity in the incident.
The case follows comments from former American National Security Agency (NSA) whistleblower Edward Snowden, who while speaking in London via videolink, said that the British agency GCHQ had unprecedented powers when it came to intercepting telephone and online communications.
Campaigners have slammed the actions powers of the intelligence agencies, saying it compromises basic privacy laws.
"This clearly violates an age-old principle of English law set down in the sixteenth century; that the correspondence between a person and their lawyer is confidential. It could mean, amazingly, that the government uses information they have got from snooping on you, against you, in a case you have brought. That affords the government an unfair advantage akin to playing poker in a hall of mirrors," a statement released by Amnesty International read.
There are suggestions that one unidentified case deals with intelligence agencies who may have activity benefited from intercepting this information.
A full hearing of the case is expected in January.
